Thread Content
Since concrete is a highly alkaline building material, concrete anti-corrosion coatings are required to have good alkali resistance, adhesion, and impermeability. In addition, the coatings themselves should also possess good weather resistance and long-lasting performance. For concrete structures located by the sea, their surface coatings must possess excellent weather resistance, being able to withstand degradation caused by sunlight and ultraviolet rays, as well as salt spray and corrosion from the marine atmosphere. They should not suffer from severe flaking, discoloration, peeling, or cracking during the effective protection period. In accordance with relevant standards such as JTJ275-2001 \"Technical Specifications for Corrosion Protection of Concrete Structures in Port Engineering\", GB50046—95 \"Design Specifications for Corrosion Protection in Industrial Buildings\", and GB50212—2002 \"Specifications for Construction and Acceptance of Corrosion Protection in Buildings\", epoxy resin coatings, polyurethane coatings, chlorinated rubber coatings, vinyl resin coatings, and acrylic resin coatings are considered suitable types of coatings. Based on experience in the corrosion protection coating of bridge concrete both domestically and internationally, the use of the following coatings can yield good results: 1. Penetrating epoxy sealant primer. Since the surface of concrete is relatively porous compared to steel, applying a penetrating sealant primer helps to enhance its surface strength, increase the adhesion between the coating and the concrete, and also improve the coating’s sealing properties and resistance to penetration. A high-solid-content, low-viscosity, highly penetrative alkali-resistant primer that penetrates deep into concrete; upon reacting and curing, it anchors and seals the substrate, providing a good surface for subsequent coating applications. 2. Epoxy putty leveling layer: Due to the uneven surface of concrete, it is necessary to use putty for leveling. Epoxy putty possesses excellent adhesion, alkali resistance, corrosion resistance, and strength, making it an ideal material for leveling. It can increase the strength of the concrete surface as well as the durability of the coating, thereby enhancing the coating’s resistance to penetration. 3. The shielded epoxy thick-film intermediate coat is a high-solid-content thick-film intermediate coat that offers excellent adhesion, alkali resistance, and impermeability; it increases the thickness of the coating layer after application, thereby enhancing the impermeability of the entire coating. 4. Aliphatic polyurethane topcoat with excellent weather resistance. This coating is often used as a topcoat in long-lasting coating systems under various harsh weather conditions. Its film exhibits outstanding resistance to salt spray and marine atmospheric corrosion; it does not degrade, flake, or change color under intense sunlight and ultraviolet radiation, allowing the coating to maintain its good appearance over time.